For a multi-component injection moulded part, the adhesion between the components is an important quality criterion. Except for assembly injection moulding, a multi-component injection moulding process has to achieve the highest possible adhesion between the components. The aim of this work was to maximize the adhesion between the components of a radar housing by optimizing the process parameters. In cooperation with Delphi Automotive Systems Austria GmbH, Mattighofen, Austria, an existing two-component injection moulding process was investigated. The radar housing consists of two components: a polybutylene terephthalate (PBT) carrier and a liquid silicone rubber (LSR) seal. Employing a fractional design of experiments, the manufacturing parameters mould temperature, hot runner and barrel temperature, back pressure, injection speed, and dosing speed of the PBT injection moulding process were examined for their impact on the adhesion between the components. In a second study, the influence of the LSR manufacturing parameters mould temperature, delay time (during mould closing), and heating time on the adhesion was analysed by using a central composite design of experiments. Within both process windows, a minimum adhesive force of 28.1 N and a maximum adhesive force of 37.0 N were measured. However, the adhesion between the components was sufficient in all experimental settings. The mould temperature in the thermoplastic process was found to be dominant. Increasing the mould temperature from 70 °C to 90 °C raised the adhesion force by 14.7 % (4.5 N). In contrast, elevated mould temperature, curing time, and delay time of the LSR-process could only lift the adhesion force from 28.1 N to 30.7 N. Moreover, higher storage time in between manufacturing and measuring caused a higher adhesion force. To emphasize, only one combination of PBT and LSR was studied in a manual transfer process. Therefore, general statements on improving the adhesion between a thermoplastic part and a liquid silicone rubber are limited.